Cardiac abnormalities are an important complication of acute brain injury from any cause, particularly intracranial bleeding and ischemic brain infarction (cerebrovascular disease). Our preliminary studies show a relationship between systemic catecholamine output doe to derangements of the sympatho-adreno-medullary axis and cardiac arrhythmias and injury following cerebral vascular lesions. By simultaneously following the metabolic and cardiac changes following acute brain damage, we will better define the incidence, types, clinical presentation and importance of the cardiac abnormalities which occur. In this way we will better understand their pathophysiology so that we can treat them effectively and improve prognosis following acute cerebral vascular disease and other causes of acute brain dysfunction.